This document relates to techniques and devices for measuring phase noise in radio frequency (RF), microwave, or millimeter signals.
RF, microwave or millimeter signals can be generated by oscillators operating in the respective spectral ranges. The output of an oscillator may be used in communications and other applications. The oscillation frequency of an oscillator can be used as a frequency reference where it is desirable that the noise of the oscillator be low and can be properly measured. A measurement apparatus for characterizing an oscillator should have low noise.